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The Palaeozoic development

 
The Franklinian Basin of North Greenland

The Franklinian Basin of North Greenland

The Palaeozoic Franklinian Basin extends from the Canadian Arctic Islands across North Greenland to Kronprins Christian Land in eastern North Greenland. Lup

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The Palaeozoic Franklinian Basin extends from the Canadian Arctic Islands across North Greenland to Kronprins Christian Land in eastern North Greenland, an E–W distance of 2000 km; only part of the Canadian segment of the basin is represented on the map. The preserved part of the succession shows that deposition in this E–W trending basin began in the latest Precambrian or earliest Cambrian and continued until at least earliest Devonian in Greenland and later Devonian to earliest Carboniferous in Canada; sedimentation was brought to a close by the mid- to late Palaeozoic Ellesmerian orogeny.
Throughout the Lower Palaeozoic, the basin in Greenland can be divided into a southern shelf and slope area and a northern deep water trough. The shelf succession is dominated by carbonates and reaches 3 km in thickness, whereas the trough deposits are dominated by siliciclastic rocks and have a total thickness of c. 8 km. The shelf–trough boundary was probably controlled by deep-seated faults, and with time the trough expanded southwards to new fault lines, with final foundering of the shelf areas in the Silurian.

Ellesmrian orogeny in North Greenland and Ellesmere Island
The Palaeozoic Ellesmerian orogeny, which brought sedimentation in the Franklinian Basin to a close, involved compression of the Lower Palaeozoic trough succession against the carbonate shelf to the south following collision with an unknown continent to the north. The resulting Ellesmerian fold belts of both North Greenland and northern Ellesmere Island are characterised by E–W to NE–SW trending chains of folds, broadly parallel to the main facies boundaries within the Franklinian Basin. In the North Greenland fold belt deformation is most intense in the north where three phases of folding are recognised and metamorphic grade reaches low amphibolite facies. Deformation decreases southwards, and the southern part of the fold belt is a thin-skinned fold and thrust zone that coincides with the region which was transitional between the platform and trough for much of the Cambrian.

Cambro–Ordovician sediments in the Caledonian fold belt in East Greenland
Cambrian–Ordovician rocks make up an approximately 4000 m thick sequence within the East Greenland Caledonian fold belt between latitudes 71o40' and 74o30'N. The sediments laid down in this Lower Palaeozoic basin are disturbed by large scale folding and faulting, but are non-metamorphic. Limestones and dolomites dominate the succession which spans the period from the earliest Cambrian to the Late Ordovician

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Cambro-Ordovician sediments in the Caledonian fold belt in East Greenland
Caledonian orogeny in East and North-East Greenland
The Caledonian fold belts on both sides of the North Atlantic developed as a consequence of collision between the continents of Laurentia to the west and Baltica to the east following closure of the proto-Atlantic ocean (Iapetus). The East Greenland Caledonian fold belt is well exposed between 70o and 81o30´N as a 1300 km long and up to 300 km wide coast-parallel belt. Large regions of the fold belt are characterised by reworked Precambrian basement rocks [74, 70, 52], overlain by middle and upper Proterozoic [46–43] and lower Palaeozoic [40] sediments. The deep-seated infrastructural levels are characterised by superimposed fold phases of several different ages, whereas the high level suprastructural levels exhibit relatively simple open folds of Caledonian age. Large scale west-directed nappes and thrust sheets interleave different levels of the Caledonian fold belt against each other and the margin of the Greenland shield. Extensional structures characterise some of the late tectonic phases. The southern and central parts of the fold belt in East Greenland mainly expose deep-seated infracrustal basement, whereas in the northernmost part of the fold belt in Kronprins Christian Land high level thin-skinned structures are preserved.

Devonian continental sediments in East Greenland
Following the Caledonian orogeny a period of extensional faulting led to the initiation of a Devonian sedimentary basin in central East Greenland. The Devonian sediments unconformably overlie Ordovician and older rocks, and are preserved in north–south trending graben-like structures.
The basin fill is of Middle and Late Devonian age [39] and consists of more than 8 km of continental siliciclastic sediments with some volcanic intervals. Four lithostratigraphic groups have been established, each corresponding to a tectonostratigraphic stage.

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Devonian continental sediments in East Greenland

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The Palaeozoic development